It is known to use light-sensitive aromatic diazonium compounds for sensitizing reproduction materials which are useful for the production of single copies, printing plates, screen printing, color proofing foils and other applications in the reproduction arts.
U.S. Pat. Nos. 3,867,147, 3,679,419 and 3,849,392 relating to mixed diazo condensates, the contents of which are hereby incorporated by reference, describe an advance overcoming disadvantages of prior art diazo compounds and reproductive layers made therefrom, i.e. poor adhesion to metal supports, tendency of metal to decompose the diazo, and high sensitivity of coated layers to moisture resulting in sensitivity to finger-printing and other tendency to damage.
Although the diazo mixed condensates of these patents fulfilled their objectives and have met commercial success, there is a continuing need in the field of graphic arts for materials exhibiting increased light sensitivity and photo-chemical speed.
For laser exposure and projection imaging, not only are higher speed printing plates necessary, they must additionally retain all of the aforementioned advantages: good stability in the form of presensitized plates, resistance to moisture, and ability to give long, uniform printing runs. Further, such plates must have strongly oleophilic images and hydrophilic non-images.
It is an object of this invention to provide higher speed printing plates than have been heretofore available.
It is another object of this invention to provide printing plates suitable for laser exposure and projection imaging.
It is still another object of this invention to provide printing plates with long uniform run characteristics, resistance to moisture and low sensitivity to metal supports in addition to the aforementioned characteristics.
It is a further object to prepare condensation products suitable for reaction with diazo monomers in the preparation of light-sensitive compounds.
It is a still further object of this invention to provide a class of novel light-sensitive diazo compounds which are inherently more sensitive to light and by the use of which the aforementioned characteristics may be obtained.
These and other objects are achieved by the invention described herein.